Question: . Consider a DAG which has already been topologically sorted, so edges go from left to right. In the lecture notes, we have seen a

. Consider a DAG which has already been topologically sorted, so edges go from left to right. In the lecture notes, we have seen a Dynamic Programming algorithm that finds the shortest path in a DAG where edges have weights associated with them. Now consider the following greedy strategies. Show that all of them fail to find the shortest path from node 1 to node n by giving appropriate small examples. You should also explain what is the value of the optimal solution compared to the greedy one. Greedy strategy 1 Set i=1 While iun, Pick the edge (i, j) with the largest j Set i=j and repeat Return the weight of the path constructed from node 1 to node n. Greedy strategy 2 Set i=1 While iun, Pick the edge (i, j) with the smallest weight Set i=j and repeat Return the weight of the path constructed from node 1 to node n. Greedy strategy 3 Set i=1 While iun, Pick the edge (i, j) with the smallest ratio weight/(-i) Set i=j and repeat Return the weight of the path constructed from node 1 to node n
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